The current study aimed at testing the limits of the so called moral foreign-language effect, according to which, using a second language makes people less emotional than using their mother tongue, which in turn promotes more utilitarian dilemma choices rather than deontological ones. For that purpose, a group of 75 German-English speakers were presented with classic moral dilemmas in either their mother tongue, German or their foreign tongue, English. It was then tested whether the subjects reacted less emotionally in the foreign language condition. Emotionality was measured through observation of pupil size changes (pupilometry measure), which has not been done before in the context of language and morality. Based on previous findings about the complexity of morality, it was also hypothesized that the factors of working memory (measured with the Digit Span Forward), language proficiency (LexTale by Lemhöfer & Broersma, 2012), moral foundations (MFQ20 by Graham et al., 2011), and emotion regulation mechanisms (CERQ-short by Garnefski et al., 2001) could moderate the expected effects. The linear and logistic regression analyses showed that there was no difference in emotional reaction between the two language conditions. Neither was there a significant difference in response patterns between the German and the English group. What seemed to primarily predict pupil size change and decision outcome was dilemma type (footbridge vs. switch), moral foundations (purity, rumination, and catastrophizing) as well as emotion regulation mechanisms (other-blame, positive reappraisal). Further research is needed to disambiguate the exact mechanisms underlying moral choices in proficient bi- and multilinguals.